
<div class="container">
    
    <div class="row" id="header">
        <div class="col-xs-12 col-sm-12 col-md-12 col-lg-12">
            <h1 class="text-center">头部信息栏</h1>
        </div>
    </div>
      
    <div class="row" id="middle">       
        <div class="col-xs-2 col-sm-2 col-md-2 col-lg-2" id="left-side-menu">

        </div>
        <div class="col-xs-10 col-sm-10 col-md-10 col-lg-10">   
            <div class="panel panel-primary center-block" style="width: 360px; margin-top: 200px">
                  <div class="panel-heading">
                        <h3 class="panel-title">登陆框</h3>
                  </div>
                  <div class="panel-body">
                        
                        <form action="" method="POST" role="form">
                            <div class="form-group">
                                <label for="">username</label>
                                <input type="text" class="form-control" name="username" id="username" placeholder="Input your username" required>
                            </div>
                            
                            <div class="form-group">
                                <label for="">password</label>
                                <input type="text" class="form-control" name="password" id="password" placeholder="Input your password" required>
                            </div>
                            <button type="submit" class="btn btn-primary center-block">Submit</button>
                        </form>
                        
                  </div>
            </div>                 
        </div>
    </div>
    
    <div class="row bg-info" id="footer">
        <div class="col-xs-12 col-sm-12 col-md-12 col-lg-12 text-center">
            <span>底部信息栏</span>
        </div>
    </div>
    
</div>
